Verizon Wireless is unveiling a ringback tone service initially to its customers in Sacramento and Southern California. Content for the Ringback Tones service is being fueled by newly expanded relationships with Warner Music Group and Sony BMG Music Entertainment.

The Ringback Tones service enables customers to personalize the sounds callers hear when they are waiting for a call to be answered. Ringback Tones can be customized based on the Caller ID, Group List or time of day, Verizon Wireless says.

Verizon Wireless is offering a catalog of more than 2,200 songs, including everything from RAP hip hop to classic rock to holiday songs. The song catalog is stocked with real music clips from Warner Music Group and Sony BMG Music Group artists.

Ringback Tones can be had for $1.99 each, plus a monthly fee of 99 cents. Ringback Tones offer subscribers unlimited use for a 1-year period. Verizon expects to expand the offering over its nationwide network by mid-2005.

In October, Lucent Technologies introduced its MiRingBack application, which enables subscribers to create caller profiles and enables them to assign different tones to different callers.

While Lucent has said the application is an ideal way for teenagers to express their individuality, it also believes the application has potential in the business world -- giving businesses the ability to convey their corporate message. Telecom New Zealand was the first carrier to launch Lucent's MiRingBack.